Field of the Invention
The invention relates to a thermal overcurrent circuit breaker with a switch housing in which a thermal expansion element, in particular a bimetal, and a manually operated snap-action switching mechanism coupled thereto, and a moving contact cooperating therewith and a fixed contact are arranged, which is connected to a first connection rail while the moving contact is contacted with a second connection rail via the thermal expansion element.
Description of the Background Art
In a thermal circuit breaker, the trigger point depends on the amount of overcurrent. With increasing current, an expansion element, in particular a bimetal, is increasingly heated up to a defined trigger point. The thermal expansion element is coupled, for example, to a trip-free, manually operable snap-action mechanism which interacts with a moving contact of a contact pair. Such a circuit breaker, also referred to as an overcurrent circuit breaker, with thermal triggering usually serves to protect loads such as electric motors, household and office equipment, power tools, power supplies and low voltage lines against overcurrent. Such circuit breakers can be designed single-pole, two-pole or three-pole and are used for rated voltages of AC (alternating current) 240V or DC (direct current) 50V with current ratings in the range between 0.1 A and 20 A.
A thermal overcurrent circuit breaker of the mentioned type is known for example from DE 27 21 162 A1, which corresponds to U.S. Pat. No. 4,167,720, and from DE 94 22 029 U1, which corresponds to U.S. Pat. No. 5,451,729. In the known circuit breakers, the connections to the contact pair, that is, to the fixed contact and via a bimetal to the moving contact carried by a contact spring, are designed as so-called tab connectors which lead out of the switch housing on a connection side opposite an ON/OFF switching rocker.
The connection of lines is made with flat plug sockets or by means of cable lugs screwed with the flat plugs.